The present invention relates to a silver halide color photographic light-sensitive material and, more particularly, to a silver halide color photographic light-sensitive material having a silver halide emulsion layer for recording optical information produced by exposure from a back side thereof, in which the recorded information has a sufficient density for reading the information after developing treatment.
In the present specification, a front side of a photographic material means the side on which a red-sensitive, green-sensitive and blue-sensitive silver halide emulsions are coated. On the other hand, a back side of a photographic material means the reverse side against the support to the front side mentioned above.
Silver halide color photographic light-sensitive materials, particularly color photographic light-sensitive materials for photographing are strongly required to give excellent images.
In addition, at photographing with cameras, a date and time of photographing are optically recorded by exposure from a back side of a photographic material for photographing. After developing process of the photographic material for photographing, this information is optically recorded on another light-sensitive material for printing, together with a subject which was exposed from the front side of the photographic material.
Although this optical record is recorded, in some cases, outside an image plane on which an image of a subject is recorded, i.e., unexposed part, the record, in many cases, is recorded inside the image plane on which a subject is recorded and at a part near the margin of the image plane (for example, right downer from the image plane).
For this reason, the record becomes very difficult to be read depending upon color, density and shape of the subject which has been exposed from the front side in some cases and, thus, there was a demand for improvement.
As an amount of a colorant to be coated, such as black colloidal silver in an antihalation layer and an amount of silver halide in an emulsion layer are reduced, an amount of light to be exposed from the back side is increased and it is possible to raise a density of the optical record to some extent.
According to this method, although the effect of raising a density of optical record from the back side is observed on a part having a lower image density of the subject which was obtained by exposure from the front side, the effect of raising a density of optical record is small on a part having a higher image density of the subject which was obtained from the front side.
In addition, it is well known that as black colloidal silver in an antihalation layer is coated at a lower amount, sharpness is reduced. Moreover, besides this reduction, an infrared absorbing density of a light-sensitive material is reduced and it becomes impossible to detect the light-sensitive material with infrared rays in a developing apparatus and, which leads to potential conveyance troubles and incorrect replenishment of a developer.
Conversely speaking, when an amount of black colloidal silver to be coated in an antihalation layer is increased in order to improve reduction in sharpness or enhance an infrared absorbing density, a density of optical record is further reduced and it becomes difficult to read it.
On the other hand, British Patent 1,519,993 has proposed an invention which improves the interlayer effect by inclusion of colloidal silver in water-impermeable layer adjacent both a green-sensitive layer and a red-sensitive layer. However, the inclusion of colloidal silver has no effect of raising a density of optical record by exposure from a back side.